2022-02-15 12:07:29

by Alexey Khoroshilov

Subject: [PATCH] NFS: remove unneeded check in decode_devicenotify_args()

Overflow check in not needed anymore after we switch to kmalloc_array().

Signed-off-by: Alexey Khoroshilov <[email protected]>
Fixes: a4f743a6bb20 ("NFSv4.1: Convert open-coded array allocation calls to kmalloc_array()")
---
fs/nfs/callback_xdr.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index f90de8043b0f..8dcb08e1a885 100644
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -271,10 +271,6 @@ __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
n = ntohl(*p++);
if (n == 0)
goto out;
- if (n > ULONG_MAX / sizeof(*args->devs)) {
- status = htonl(NFS4ERR_BADXDR);
- goto out;
- }

args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
if (!args->devs) {
--
2.7.4

2022-02-16 15:45:08

by Anna Schumaker

Subject: Re: [PATCH] NFS: remove unneeded check in decode_devicenotify_args()

Hi Alexey,

On Tue, Feb 15, 2022 at 5:17 AM Alexey Khoroshilov
<[email protected]> wrote:
>
> Overflow check in not needed anymore after we switch to kmalloc_array().

Don't we still need the overflow check since 'n' is used in the
for-loop end condition farther down in this function?

Thanks,
Anna

>
> Signed-off-by: Alexey Khoroshilov <[email protected]>
> Fixes: a4f743a6bb20 ("NFSv4.1: Convert open-coded array allocation calls to kmalloc_array()")
> ---
> fs/nfs/callback_xdr.c | 4 ----
> 1 file changed, 4 deletions(-)
>
> diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
> index f90de8043b0f..8dcb08e1a885 100644
> --- a/fs/nfs/callback_xdr.c
> +++ b/fs/nfs/callback_xdr.c
> @@ -271,10 +271,6 @@ __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
> n = ntohl(*p++);
> if (n == 0)
> goto out;
> - if (n > ULONG_MAX / sizeof(*args->devs)) {
> - status = htonl(NFS4ERR_BADXDR);
> - goto out;
> - }
>
> args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
> if (!args->devs) {
> --
> 2.7.4
>